Emergency Lighting Methods and Systems

ABSTRACT

Described herein are systems and methods of emergency lighting comprising one or more light emitting diode (LED) lamps with a low-maintenance or maintenance-free battery. In one aspect, the battery is a sealed lead-acid battery. In one aspect, the battery is an absorbent glass mat (AGM) battery. In one aspect, the LED lamps can be a part of a LED assembly that can include an integrated voltage regulator. In one aspect, the one or more lamps are parabolic aluminized reflector luminares, or PAR lights such as PAR 46 light assemblies.

CROSS REFERENCE TO RELATED APPLICATION

This application claims benefit of and priority to U.S. ProvisionalPatent Application No. 61/147,276, filed Jan. 26, 2009, which is herebyincorporated by reference in full and made a part hereof.

BACKGROUND

Nuclear facilities are required in the U.S. to monitor the effectivenessof maintenance at nuclear power plants. In 1991, the U.S. NuclearRegulatory Commission (NRC) published the maintenance rule (MRule) asSection 50.65, “Requirements for Monitoring the Effectiveness ofMaintenance at Nuclear Power Plants,” of 10 CFR Part 50, “DomesticLicensing of Production and Utilization Facilities.” The NRC'sdetermination that a maintenance rule was needed arose from theconclusion that proper maintenance is essential to plant safety. Asdiscussed in the regulatory analysis for this rule, there is a clearlink between effective maintenance and safety as it relates to suchfactors as the number of transients and challenges to safety systems andthe associated need for operability, availability, and reliability ofsafety equipment. In addition, good maintenance is also important inproviding assurance those failures of other than safety-relatedstructures, systems, and components (SSCs) that could initiate oradversely affect a transient or accident are minimized. Minimizingchallenges to safety systems is consistent with the NRC'sdefense-in-depth philosophy. Maintenance is also important to ensurethat design assumptions and margins in the original design basis aremaintained and are not unacceptably degraded. Therefore, nuclear powerplant maintenance is clearly important in protecting public health andsafety.

Regulatory guide 1.160 of the MRule provides that examples of SSCs thatshould be considered include communications and emergency lightingsystems, which are necessary to successfully mitigate accidents andtransients and to use the emergency operating procedures (EOPs),although they may not directly address the accident or transient, or notbe explicitly mentioned in the EOPs.

Appendix R to Part 50—Fire Protection Program for Nuclear PowerFacilities Operating Prior to Jan. 1, 1979 requires that “emergencylighting units with at least an 8-hour battery power supply shall beprovided in all areas needed for operation of safe shutdown equipmentand in access and egress routes thereto.” The general purpose ofemergency lighting systems is to provide sufficient lighting of desiredquality in all areas of a station, indoors and outdoors, for normal,essential, and emergency conditions. AC station lighting is the normallighting system used throughout a facility. Generally, normal AClighting cabinets are energized from the non-ESF (Engineered SafetyFeatures) 480-volt motor control centers.

AC emergency (or standby) station lighting is provided for stationoperation during a loss of normal AC auxiliary power. It is limited tothe lighting required for the control and maintenance of ESF equipment(such as the ESF switchgear, emergency cooling equipment, controlequipment, etc.) and for the access routes to this equipment. Generally,it is energized from the 480-Volt ESF motor control centers and thusreceives power from the diesel generators when, and if, the sources ofnormal AC auxiliary power fail. Control room emergency lighting systemsare similar to normal lighting systems except that the source of ACpower is supplied from the engineered safety features power distributionsystem. These lights are normally in service at all times.

8-hour balance of plant (BOP) and safe shutdown battery emergencylighting units are provided in various locations in sufficient quantityto provide supplemental lighting for maintenance and supervision of bothBOP and safe shutdown equipment. The battery emergency lighting systemin the control room consists of battery operated lighting units locatedstrategically within the control room. The units are normallyde-energized and operated automatically upon failure of the ESF ornon-ESF AC lighting systems.

Current emergency lighting systems are generally comprised of wet-cellbatteries and incandescent lights. These systems require periodicmaintenance and generally degrade over time. In some instances, theselighting systems are not capable of providing the desired eight hours ofemergency lighting.

Therefore, systems and methods that overcome challenges found in theart, some of which are described above, are desired.

SUMMARY

Described herein are systems and methods of emergency lightingcomprising one or more light emitting diode (LED) lamps with alow-maintenance or maintenance-free battery. In one aspect, the batteryis a sealed lead-acid battery. In one aspect, the battery is anabsorbent glass mat (AGM) battery. In one aspect, the LED lamps can be apart of a LED assembly that can include an integrated voltage regulator.In one aspect, the one or more lamps are parabolic aluminized reflectorluminares, or PAR lights such as PAR 46 light assemblies.

Additional advantages will be set forth in part in the description whichfollows or may be learned by practice. The advantages will be realizedand attained by means of the elements and combinations particularlypointed out in the appended claims. It is to be understood that both theforegoing general description and the following detailed description areexemplary and explanatory only and are not restrictive, as claimed.

BRIEF DESCRIPTION OF TILE DRAWINGS

The accompanying drawings, which are incorporated in and constitute apart of this specification, illustrate embodiments and together with thedescription, serve to explain the principles of the methods and systems:

FIG. 1 illustrates one embodiment of an emergency lighting system; and

FIG. 2 illustrates a simplified block diagram for one embodiment of anemergency lighting system.

DETAILED DESCRIPTION

Before the present methods and systems are disclosed and described, itis to be understood that the methods and systems are not limited tospecific synthetic methods, specific components, or to particularcompositions. It is also to be understood that the terminology usedherein is for the purpose of describing particular embodiments only andis not intended to be limiting.

As used in the specification and the appended claims, the singular forms“a,” “an” and “the” include plural referents unless the context clearlydictates otherwise. Ranges may be expressed herein as from “about” oneparticular value, and/or to “about” another particular value. When sucha range is expressed, another embodiment includes from the oneparticular value and/or to the other particular value. Similarly, whenvalues are expressed as approximations, by use of the antecedent“about,” it will be understood that the particular value forms anotherembodiment. It will be further understood that the endpoints of each ofthe ranges are significant both in relation to the other endpoint, andindependently of the other endpoint.

“Optional” or “optionally” means that the subsequently described eventor circumstance may or may not occur, and that the description includesinstances where said event or circumstance occurs and instances where itdoes not.

Throughout the description and claims of this specification, the word“comprise” and variations of the word, such as “comprising” and“comprises,” means “including but not limited to,” and is not intendedto exclude, for example, other additives, components, integers or steps.“Exemplary” means “an example of” and is not intended to convey anindication of a preferred or ideal embodiment. “Such as” is not used ina restrictive sense, but for explanatory purposes.

Disclosed are components that can be used to perform the disclosedmethods and systems. These and other components are disclosed herein,and it is understood that when combinations, subsets, interactions,groups, etc. of these components are disclosed that while specificreference of each various individual and collective combinations andpermutation of these may not be explicitly disclosed, each isspecifically contemplated and described herein, for all methods andsystems. This applies to all aspects of this application including, butnot limited to, steps in disclosed methods. Thus, if there are a varietyof additional steps that can be performed it is understood that each ofthese additional steps can be performed with any specific embodiment orcombination of embodiments of the disclosed methods.

The present methods and systems may be understood more readily byreference to the following detailed description of preferred embodimentsand the Examples included therein and to the Figures and their previousand following description.

Described herein are systems and methods of emergency lightingcomprising one or more light emitting diode (LED) lamps with alow-maintenance or maintenance-free battery. In one aspect, the batteryis a sealed lead-acid battery such as, for example, a lead-calciumbattery. In one aspect, the battery is an absorbent glass mat (AGM)battery. In one aspect, the LED lamps can be a part of a LED assemblythat can include an integrated voltage regulator. In one aspect, the oneor more lamps are parabolic aluminized reflector luminares, or PARlights such as PAR 46 light assemblies.

Embodiments described herein have low power requirements, lifetimes ofabout 100,000 hours, lighting output that meets or exceeds comparableincandescent lamps and maintains an almost constant light output duringthe entire discharge period of the battery. In one aspect, the use ofimmobilized, sealed lead-acid batteries generally eliminates thehandling of electrolyte and the potential for electrolyte spillage orleakage. In one aspect, the use of AGM battery technology results inhigher power density and higher seismic resistance for the batteries ascompared to existing flooded (wet) cell batteries. In one aspect,embodiments described herein meet or exceed Appendix R to Part 50—FireProtection Program for Nuclear Power Facilities Operating Prior to Jan.1, 1979, which requires that “emergency lighting units with at least an8-hour battery power supply shall be provided in all areas needed foroperation of safe shutdown equipment and in access and egress routesthereto.”

FIG. 1 illustrates one embodiment of an emergency lighting system 100.This embodiment comprises a battery 102, one or more lamp assemblies104, and a battery 106. In one aspect, the battery 102 is a Power-SonicPS12400 battery as manufactured by Power-Sonic Corporation, 7550Panasonic Way, San Diego, Calif. 92154, though other batteries can alsobe used such as the Genesis G42EP as available from EnerSys of Reading,Pa., among others. The PS12400 battery is rated 480 watts at 12 VDC and40 amp-hours. It has a power density of 15.5 watts/pound. It has animmobilized electrolyte comprising absorbed glass mat. It is generallymaintenance free. The one or more lamp assemblies 104 are comprised of 4watt LED lamps in a PAR 46 sealed beam package such as thePAR46-72-XCW-001 assembly as available from Ledtronics, Inc. of St.Louis, Mo., though other light assemblies can be used such as the F61224floodlight as available from The LED Light, Inc. of Carson City, Nev.,among others. The Ledtronics PAR46-72-XCW-001 LED sealed beam electricalconnections are screw terminal type and non-polarized. In one aspect,the LEDs are rated 10-85 V AC/DC with a current draw of about 317 to 330mA. In one aspect, the lamp assemblies can have a lifetime of about100,000 hours. Paired with the PS12400 battery described above, thesystem can have a runtime of about 63 hours with two lamp assemblies 104and about 42 hours with three lamp assemblies 104. Further comprisingone embodiment of the system 100 is a battery charger 106, as are knownto those of ordinary skill in the art. In one aspect, the charger can bea 12-volt DC constant voltage charger. The charger should meet chargevoltage and current limits for the battery selected per the batterymanufacturer's specifications. In one aspect, the charger 106 comprisesa battery protection feature of load disconnect at 10.5 vdc (for a12-volt battery) to prevent battery damage from deep discharges. In oneaspect, the charger can return a 40 AH battery to fully chargedcondition from 10.5 vdc within 24 hours. In one aspect, the system 100further comprises a battery disconnect switch and a load disconnectswitch to isolate the battery from the charger. This is to eliminatedisconnecting the battery at the terminals during battery internalresistance checks and to prevent discharge due to parasitic chargerload. In one aspect, the system 100 can comprise a momentary contacttest switch for performing functional testing.

FIG. 2 illustrates a simplified block diagram for one embodiment of anemergency lighting system. The system 200 comprises one or more lampassemblies 202. In various aspects, the system comprises one, two,three, four, etc. lamp assemblies 202. The system 200 may comprise avoltage regulator 204 that can be separate from or integrated into alamp assembly 202. Further comprising an embodiment of the system is aload disconnect switch 206 that can be controlled 208 such that itcloses and causes the light assemblies 202 to become energized upon theloss of AC voltage 210. Similarly, load disconnect switch 206 can beused to disconnect a battery 212 from the lamp assemblies 202, or tobypass the battery 212 (in cooperation with battery disconnect switch216) and power the lamp assemblies 202 directly from a regulated powersource such as a transformer/regulator/charger/control 214 as shown inFIG. 2. It is to be appreciated that while switches 206 and 216 areshown as single devises in FIG. 2, they may each be comprised of one ormore switches, relays, contacts, coils and accompanying devices as knownto one of ordinary skill in the art. Thetransformer/regulator/charger/control 214 comprises one or moretransformers generally used to step down incoming AC voltage 210, one ormore rectifiers as known to one of ordinary skill in the art to rectifythe AC voltage to DC, and a regulator, as known to one of ordinary skillin the art, to regulate the DC voltage. The output DC voltage can beused to charge the battery 212 or directly power the light assemblies202 (such as doing a test function). Thetransformer/regulator/charger/control 214 can further comprise a controlboard configured to control operation of the system 200 includingsensing the loss of AC voltage 210 and causing the lamp assemblies 202to energize. In one aspect, the transformer/regulator/charger/control214 comprises an integrated solid-state system. The charger componentcan have multiple charge rates and be automatically controlled. In oneaspect the DC output of the transformer/regulator/charger/control 214can be fused 218 or otherwise protected from overcurrent conditions. Inone aspect, the transformer/regulator/charger/control 214 includes alow-voltage battery cutoff. In one aspect, thetransformer/regulator/charger/control 214 includes brownout sensitivitycontrol. Battery disconnect switch 216 can be used to isolate thetransformer/regulator/charger/control 214 from the battery 212 or tobypass the battery 212 and directly energize the map assemblies 202through the transformer/regulator/charger/control 214. In one aspect,the AC power source 210 may comprise overcurrent protection (e.g., afuse, breaker, etc.) 220 so as to limit current in the event of a faultin the system 200.

While the methods and systems have been described in connection withpreferred embodiments and specific examples, it is not intended that thescope be limited to the particular embodiments set forth, as theembodiments herein are intended in all respects to be illustrativerather than restrictive.

Unless otherwise expressly stated, it is in no way intended that anymethod set forth herein be construed as requiring that its steps beperformed in a specific order. Accordingly, where a method claim doesnot actually recite an order to be followed by its steps or it is nototherwise specifically stated in the claims or descriptions that thesteps are to be limited to a specific order, it is no way intended thatan order be inferred, in any respect. This holds for any possiblenon-express basis for interpretation, including: matters of logic withrespect to arrangement of steps or operational flow; plain meaningderived from grammatical organization or punctuation; the number or typeof embodiments described in the specification.

Throughout this application, various publications are referenced. Thedisclosures of these publications in their entireties are herebyincorporated by reference into this application in order to more fullydescribe the state of the art to which the methods and systems pertain.

It will be apparent to those skilled in the art that variousmodifications and variations can be made without departing from thescope or spirit. Other embodiments will be apparent to those skilled inthe art from consideration of the specification and practice disclosedherein. It is intended that the specification and examples be consideredas exemplary only, with a true scope and spirit being indicated by thefollowing claims.

What is claimed is:
 1. An emergency lighting system comprising: alead-acid battery, wherein said battery has an immobilized electrolyte;one or more LED lamp assemblies; and a control device, wherein saidcontrol device causes said battery to energize said one or more LED lampassemblies at a constant lumen level for a sustained period of time. 2.The emergency lighting system of claim 1, wherein the sustained periodis at least eight hours.
 3. The emergency lighting system of claim 1,wherein said emergency lighting system complies with Appendix “R” of 10CFR Part
 50. 4. The emergency lighting system of claim 1, wherein saidbattery is a maintenance-free battery comprising absorbed glass mat forimmobilization of the electrolyte.
 5. The emergency lighting system ofclaim 1, further comprising an input AC voltage source, a transformerand a rectifier, wherein said transformer and rectifier convert said ACvoltage to DC voltage.
 6. The emergency lighting system of claim 5,further comprising a battery charger, wherein said battery charger usesthe DC voltage to charge the battery.
 7. The emergency lighting systemof claim 5, wherein the DC voltage is 12-volt DC voltage.
 8. Theemergency lighting system of claim 5, wherein said control devicemonitors the AC voltage and said control device causes the battery toenergize the one or more LED lamp assemblies when the AC voltage dropsbelow a threshold level.
 9. The emergency lighting system of claim 1,further comprising one or more disconnect switches, wherein saiddisconnect switches can be used to isolate the battery from the rest ofthe emergency lighting system,
 10. The emergency lighting system ofclaim 1, wherein the one or more LED lamp assemblies comprise two LEDlamp assemblies.
 11. The emergency lighting system of claim 1, whereinthe one or more LED lamp assemblies comprise one or more PAR-46 lampassemblies.
 12. The emergency lighting system of claim 1, wherein saidcontrol device causes said emergency lighting system to provide lightingin a nuclear power facility during a power outage.